Palm has posted an updated OS for the Treo 650 Verizon version that fixes all my bluetooth issues on the M. The new OS version is 1.05a. It is located here:
http://www.palm.com/us/support....html
I have only used it for ten or fifteen minutes today, but the problems of the phone disconnecting in a few seconds seem solved, the antenna signal strength now displays on the vehicle nav screen and so forth.
Updating was fairly easy. Reinstalling third party applications that do not conform to the standard Palm backup-and-reinstall system was a time consuming pain.
But the phone works now!